In the field of electrical devices, already available are various devices shaped as modular components and, thus, interchangeable, to be snapped into position in receptacles, outlet boxes or wall plates of the type normally employed in household electrical wiring systems and, generally, in constructions of the residential type. Similar devices of various kind are the object of a previous Italian patent of Nov. 15, 1969 and can be of multiple dimension with respect to the base module for conventional accessories, such as wall switches, sockets and the like; they may be mounted side by side with these accessories in the windows of common receptacles for a perfect harmonization of the installation.
In any event, these electrical devices remain operative as long as they are connected to the electrical network and are mounted in the receptacle or in the outlet box. Accordingly, once they are detached from the electrical network and from the receptacle or outlet box, they become useless, because they are no longer suitable of employment in some other auxiliary function, complementary or of emergency.